This invention relates to an assistant pedal system and, more particularly, to an assistant pedal system which assists a child to selectively depress pedals of a keyboard musical instrument.
Pieces of music are played on a keyboard musical instrument with thumbs, fingers and feet. The manufacturers design most of the keyboard musical instruments to be played by adults. However, parents want their children to take lessens on the keyboard musical instruments from an early age. Children""s legs are so short that they feel it difficult to step on the pedals of the keyboard musical instrument. It is required to either buy a small-sized keyboard musical instrument or insert an assistant pedal system between children""s feet and the pedals of the keyboard musical instrument. To buy the assistant pedal system is less expensive rather than to buy the small-sized keyboard musical instrument.
FIG. 1 shows a typical example of the assistant pedal system. In the following description, term xe2x80x9cfrontxe2x80x9d is indicative of a point closer to a keyboard musical instrument than a xe2x80x9crearxe2x80x9d point. Term xe2x80x9cfore-and-aft directionxe2x80x9d is a virtual line connected between a front point and a corresponding rear point. Term xe2x80x9clateralxe2x80x9d modifies a direction crossing the fore-and-aft direction at right angle on a virtual horizontal plane, and term xe2x80x9cup-and-downxe2x80x9d modify another direction normal to the virtual horizontal plane. In the prior art assistant pedal system 100 shown in FIG. 1, the terms xe2x80x9cfrontxe2x80x9d and xe2x80x9crearxe2x80x9d are corresponding to the right side and left side, respectively.
The prior art assistant pedal system 100 largely comprises a stationary frame 100a, a movable assistant pedal mechanism 100b, a position adjuster 100c, a telescopic force transmission mechanism 100d and a coupling 100e. The stationary frame 100a is put on a floor, and the position adjuster 100c is connected at the lower end thereof to the stationary frame 100a and at the upper end thereof to the movable assistant pedal mechanism 100b. Thus, the movable assistant pedal mechanism 100b is spaced from the stationary frame 100a in the vertical direction by means of the position adjuster 100c. Since the position adjuster 100c is variable in the distance between the lower end and the upper end, the position adjuster 100c can vary the height of the assistant pedal mechanism 100d from the floor.
The telescopic force transmission mechanism 100d is connected at the upper end thereof to the assistant pedal mechanism 100b and at the lower end thereof to pedals 106 of a keyboard musical instrument such as a piano. The telescopic force transmission mechanism 100d is variable in distance between the upper end and the lower end. The coupling 100e is provided in association with the telescopic force transmission mechanism 100b, and fixes the telescopic force transmission mechanism to a given length.
When a user feels the assistant pedal mechanism 100b too low, the user lifts the assistant pedal mechanism 100b, and spaces the assistant pedal mechanism 100b from the stationary frame 100a. The distance between the pedals 106 and the assistant pedal mechanism is increased, and, accordingly, the telescopic force transmission mechanism 100d is elongated. On the other hand, when the user feels the assistant pedal mechanism 100b too high, the user pushes down the assistant pedal mechanism 100b, and the telescopic force transmission mechanism 100d is shrunk. When the user feels the assistant pedal mechanism 100b to be adjusted to the suitable position, the user fixes the telescopic force transmission mechanism 100d to the length by using the coupling 100e, and starts to perform a piece of music on the piano. Thus, the coupling 100e is required for the telescopic force transmission mechanism 100b. 
The assistant pedal mechanism 100b includes assistant pedals 101, a bracket 102 and a foot rest 103. The bracket 102 projects from the front end of the foot rest 103, and the assistant pedals 101 rearward projects from the bracket 102. Although only one assistant pedal 101 is illustrated in FIG. 1, the other assistant pedals 101 hide themselves behind it. The assistant pedals 101 are swingably connected at the front ends thereof to the bracket 102, and a player selectively steps on the rear portions of the assistant pedals 101.
The stationary frame 100a is formed with a guide groove 100h, and the foot rest 103 is also formed with a guide groove (not shown). The position adjuster 100c includes a link work 105 and a manipulator (not shown). A user manipulates the manipulator for actuating the link work 105. The link work 105 has plural bars 105A and connectors 105B/105C. The plural bars 105A cross each other, and are connected at the intermediate portion by means of the connector 105B. The connector 105B permits the bars 105A to be rotated thereabout. The bars 105A are rotatably connected to at lower ends thereof to the stationary frame 100a and at the upper ends thereof to the foot rest 103 by means of the connectors 105C. The connectors 105C are slidably received in the guide grooves 100h, and the other connectors 105C are simply rotatably connected to the stationary frame 100a and foot rest 103. While the user is actuating the frame work 105 by means of the manipulator, the pins 105C slide in the guide grooves 100h in the fore-and-aft direction, and permit the bars 105A to change the relative position therebetween.
The telescopic force transmission mechanism 100d includes couplers 107, tubes 108a, rods 108b and coil springs 108c. The couplers 107 are respectively connected to the lower ends of the rods 108b, and the pedals 106 are coupled to the rods 108b by means of the couplers 107, respectively. On the other hand, the tubes 108a are connected at the upper ends thereof to the assistant pedals 101, and the rods 108b are slidable in the tubes 108a in the up-and-down direction. Although the tubes 108a and rods 108b are rigid, the total length of each tube 108a and the associated rod 108b is telescopically variable. The coil springs 108c are wound on the outer surfaces of the tubes 108a, and are secured to the tubes 108a, respectively so as to urge the associated tubes 108a and, accordingly, the assistant pedals 101 upwardly. The tubes 108a are secured to the associated rods 108b by means of the coupling 100e so that the force exerted on the assistant pedals 101 is transmitted through the tubes 108a, rods 108b and couplers 107 to the pedals 106 of the piano.
The coupler 100e includes supporting plates 109a/109b and long bolts 109c. The supporting plates 109a/109b are respectively fixed to the lower surface of the foot rest 103 and the tubes 108a, and are formed with the holes. The long bolts 109c passes through the holes, and are secured into the threaded holes formed in the tubes 108a. The tips of the long bolts 109c reach the rods 108b, and are pressed against the associated rods 108b. Thus, the tubes 108a are respectively coupled to the rods 108b by means of the long bolts 109c. 
A child is assumed to practice the piano. The prior art assistant pedal system 100 is placed on the floor, and his or her parent loosens the long bolts 109c. The rods 108b are released from the associated tubes 108a, and become movable. The parent aligns the couplers 107 with the pedals 106 of the piano, and couples the rods 108b to the pedals 106 by means of the couplers 107. Subsequently, the parent actuates the link work 105 with the manipulator (not shown), and moves the assistant pedal mechanism 100b in the up-and-down direction. When the assistant pedals 101 are adjusted to the suitable positions for the child, the parent turns the long bolts 109c, and secures the rods 108b to the tubes 108a. Thus, the child gets ready for practicing a piece of music on the piano.
A problem is encountered in the prior art assistant pedal system in that the adjusting work is complicated and time consuming. As described hereinbefore, the user loosens the long bolts 109c, adjusts the assistant pedals 101 to the suitable positions, and secures the rods 108b to the tubes 108a by means of the long bolts 109c, again. The problem is serious in a concert where many children participate the concert program. Whenever the pianist is changed from a child to another child, an assistant readjusts the assistant pedals 101 to different positions suitable to the next child.
It is therefore an important object of the present invention to provide an assistant pedal system, which is easy to adjust assistant pedals to a pianist.
To accomplish the object, the present invention proposes to take up difference by changing a route along which a flexible force transmitter extends.
In accordance with one aspect of the present invention, there is provided a n assistant pedal system for transmitting a force to at least one pedal of a keyboard musical instrument comprising a foundation having a major surface, an assistant pedal mechanism having at least one assistant pedal moved between a rest position and an end position, a position adjuster connected at one end thereof to the foundation and at the other end thereof to the assistant pedal mechanism and actuated to vary a distance between the aforesaid one end and the other end, and a flexible force transmitter connected at one end thereof to the at least one assistant pedal, transmitting a force exerted on the assistant pedal to the aforesaid at lest one pedal of the keyboard musical instrument for moving the aforesaid at least one pedal from a rest position and automatically changing a route between the aforesaid at least one assistant pedal and the pedal depending upon the distance between the foundation and the assistant pedal mechanism.